The present invention generally relates to roller coater type apparatus which are used to apply laminate to a substrate, and more particularly to a roller coater for coating one or both sides of a sheet metal strip fed along a predetermined path, such as for example into a press.
In the metal forming industry, apparatus commonly known as roller coaters are used to apply a lubricant type laminate to sheet metal strip substrate. The lubricant laminated sheet metal is then typically fed into a press which punches and forms the sheet metal into patterns as desired. The lubricant performs the desirable function of lubricating the tooling of the press when it is working the metal. Sometimes it is desirable to switch the type of lubricant depending upon the particular types of operations being performed to the metal. It is usually desirable to coat both sides of the sheet metal strip with lubricant although it is occasionally desirable to coat only one side of sheet. It may also be desirable to change the width of the laminate application depending upon the width of the metal strip or the operations of the downstream press.
In the sheet metal lubrication industry, the typical roller coater apparatus includes upper and lower roller coater assemblies for application of lubricant to both sides of the sheet metal substrate. The upper and lower roller coaters include respective applicator rolls which pinch the sheet metal strip therebetween to apply lubrication to the top and bottom sides of the sheet metal strip. The applicator rolls are journalled in bearings at their ends for rotation about parallel rotational axes.
Heretofore, prior roller coater apparatus have had several drawbacks. One drawback is that there is typically a substantial amount of downtime and labor required when changing applicator rolls to apply different types of laminate. Another drawback is that roller coaters have less than desirable lubricant application that is either non-uniform or uneven, particularly where a small application rate is desired. This often results in wasted lubricant or alternatively a poorly lubricated press. Yet another drawback is that roller coater apparatus have not been able to adapt to changes in feed of the sheet metal strip.
It is therefore the general objective of the present invention to provide a more practical and reliable roller coater apparatus that is well suited to apply lubricant to sheet metal strip.
According to certain aspects of the present invention, it is an object to provide a roller coater apparatus that applies a more controlled amount of lubricant on sheet metal strip.
According to another aspect of the present invention, it is an object of the present invention to provide a roller coater apparatus that allows operators to easily change an applicator roll with a replacement roll or a different type of roll.
According to yet another aspect of the present invention, it is an object of the present invention to provide a roller coater apparatus that better accommodates vertical height fluctuations in the sheet metal strip during operation.
Accordingly, the present invention is directed in part towards a novel support arrangement for the applicator roll of a roller coater apparatus which is used to apply lubricant or other laminate to metal strip. The apparatus generally includes top and bottom roller coaters which are adapted to pinch metal strip there between in an engaged position. The support of the applicator roll is accomplished by three contact points arranged in a triangular configuration such that the applicator roll may be carried without the need for a physical connection between the applicator roll and the roller coater apparatus. The first contact point is provided by the metal strip itself A pair of supports such as support rolls or bearing rollers provide the second and third contact points and allow the applicator roll to rotate between the three contact points to apply lubricant to the metal strip.
The present invention is also directed towards the provision of a novel lubricant applicator assembly which generally comprises a transfer roll and a dispensing head. The transfer roll contacts the applicator roll along a laminate transfer line generally parallel with the rotational axis of the applicator roll. The dispensing head has a recessed surface which closely receives the outer cylindrical surface of the transfer roll. The dispensing head includes a longitudinal outlet in the recessed surface which receives laminate and applies laminate to the transfer roll, which in turn applies laminate to the applicator roll.
The present invention is also directed in part towards the provision of pneumatic vertical floatation of the top and bottom roller coater assemblies of a roller coater apparatus. According to this aspect, the roller coater apparatus includes top and bottom roller coater assemblies which are adapted to pinch metal strip there between to selectively coat one or both sides of the metal strip with lubricant. A pneumatic cylinder assembly is provided that is capable of moving upward and downward along with variations with the vertical type of the flow of the metal strip. To accomplish this, at least one pneumatic cylinder assembly is provided that includes a top and a bottom pneumatic cylinder. The top pneumatic cylinder operates the upper roller coater assembly while the bottom pneumatic cylinder operates the lower roller coater assembly. The compartments of the top and bottom cylinders are operatively connected in order to allow the cylinders to move upward and downward in unison without changing the pinching force applied to the sheet metal strip there between.
The present invention is also directed towards an improved control system for controlling the rate at which lubricant is applied to sheet metal strip. According to this aspect, a lubricant supply assembly generally includes a control valve, a manifold connecting the output flow of the control valve to at least one head in the roller coater, and means for modulating the valve between at least two different flow regulating positions to set an application rate of the laminate or lubricant. The modulating means may take the form of an electronic controller that is controllable to change the application rate if so desired.
Other object and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.